1. Field of the Invention
The present invention relates to packaging of image sensor components, and more particularly, to a package structure for optical image sensing integrated circuit devices with asymmetrically sealing glue coating.
2. Description of the Prior Art
Image sensor components such as charge coupled devices or CMOS image sensors have been widely applied to electronic products for converting light into electrical signals. The applications of image sensor components include monitors, cell phones, transcription machines, scanners, digital cameras, and so on. As size of image sensing components continues to shrink, the back end packaging processes for the image sensing components becomes more and more critical. It is known that the prior art image sensor packaging processes such as Plastic Leaded Chip Carrier (PLCC) or Ceramic Leaded Chip Carrier (CLCC) have poor performance and low yield.
FIG. 1 illustrates a prior art package structure of an image sensing component. As shown in FIG. 1, the image sensing component 1 is attached onto a plastic or ceramic carrier substrate 2. Typically, the image sensing component 1 is placed in a recessed area of the carrier substrate 2 and is sealed by a glass lid 3. The inner circuitry of the image sensing component 1 is connected to outer circuitry via bonding wires 4.
The above-described conventional package structure of an image sensing component has several drawbacks. For example, the packaging procedure is complicated, leading to long manufacture cycling time. Contaminations such as dusts or particles are easily introduced during packaging, thereby reducing product yields. Furthermore, the package size according to the prior art is too large.